Adding 3 Prong GFI to Old Wiring Where None Existed Before

I want to pull out the recessed medicine cabinet in the bathroom of my Mom's 1960-built home (2 prong ungrounded outlets).

The cabinet has a horizontal light on top, with a push-button switch on one end of the fixture, and a 2-prong outlet on the other.

Whatever I replace the cabinet with, I'll need to add new lighting, so I'll also have to add a switch to control it.

I thought I would run the in-wall wiring that feeds the current fixture down to a new 2-gang box for a switch (to control the new lighting), and a GFI outlet.

Two things with this that I have problems with:

1) From what I've read, it is okay by code to replace an existing 2-prong outlet with a 3-prong GFI, as long as it's labeled "no equipment ground," and no further modifications are made. I'm effectively adding an outlet where none existed before, so this seems to shoot a hole into my plans. What are my options here?

2) I won't know until I pull out the cabinet how much slack I have with the existing wiring. My guess is that I would have to add to it to give me the length needed to reach the new outlet & switch further down the wall (to the same height as the other switches in the room).

What are the rules for doing an in-wall splice?

I know any connection needs to be in a j-box, but can that j-box stay hidden in the wall, or do I need to make it accessible and put a blank cover plate on it? I suppose the other option would be to put the GFI in that single-gang j-box with the original wiring, then feed new wiring from it down to the switch and up to the new lights.

I don't like the idea of a blank j-box cover or GFI high up on the wall - obviously only having the 2-gang switch/outlet would be the most attractive.

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What does she have currently for a main panel, is it a Breaker or Fuse panel? As for just adding the GFCI outlet, you can, but really need to know more info as to is the wall tiled, Plaster & Lathe, Gyprock (Gypsum board with Portland Cement over it), or some other type of material.

Pictures of what you are dealing with wall wise, helps. As for the junction box on those old cabinets, or even the newer ones with built in lighting, the access cover on them is inside the cabinet, not on top where you would of course would have to pull the cabinet to get to it. If you did it with your current setup, you would have to of course probably pull the cabinet, to allow you to route the wiring down to the GFCI outlet, so that you can then of course be without an outlet or lighting in that cabinet.

So you have to weigh your evils on this job, just like when I redid our bath. The person that put in the old medicine cabinet, did not even secure the BX that went into the top. They just left the wire nuts hanging out of it, with electrical tape wrapped around the nuts. The Home Inspector never even took the access cover off inside the cabinet to look at it. He just wrote it up as suggest to install GFCI protection for that circuit.

I was so glad to finally get rid of that mess, and run all new wiring with two outlets in the bath, with one to the left of the sink, and the one to the right is the GFCI outlet.

What does she have currently for a main panel, is it a Breaker or Fuse panel?

Old fuse box was replaced with breakers several years ago.

Quote:

Originally Posted by gregzoll

As for just adding the GFCI outlet, you can, but really need to know more info as to is the wall tiled, Plaster & Lathe, Gyprock (Gypsum board with Portland Cement over it), or some other type of material.

Sheetrock over studs.

Quote:

Originally Posted by gregzoll

Pictures of what you are dealing with wall wise, helps. As for the junction box on those old cabinets, or even the newer ones with built in lighting, the access cover on them is inside the cabinet, not on top where you would of course would have to pull the cabinet to get to it. If you did it with your current setup, you would have to of course probably pull the cabinet, to allow you to route the wiring down to the GFCI outlet, so that you can then of course be without an outlet or lighting in that cabinet.

Thought we may just pull the cabinet, repair the sheetrock, and hang a nice framed mirror, with a light sconce on each side - controlled by the switch... She's way out of state; I have no pics to post.

So code mentions hidden, in-wall connections are okay if you use Ideal wire nuts?

dbb1959, we did the same thing. Gutted the whole bath, and when it came time to do the sink area, we hung a mirror and put up a three light sconce. The only thing missing from the picture, is the towel ring above and between the light switches and outlet. Power comes up where the switch box is, then goes from that outlet across over to the other. I really wished when I did the bath, that I placed one on the wall across from the basin, next to the heat register on that wall, so that if anyone wanted to plug in a bath whirlpool, they could, without having to run the cord back behind the toilet, or over the toilet.

Power comes up where the switch box is, then goes from that outlet across over to the other.

Nice job, gregzoll!

But the (always hot) power to her medicine cabinet is located above it, where the fluorescent fixture is - the fixture itself contains the push button to turn the light on and off, so it would be up there that I would have to add the j-box and cover plate to connect the extra length of wiring to take down to a new wall switch. I have no idea where that cabinet wiring feeds from - I suspect from the ceiling light and fan switches next to the door on the adjacent wall...

But the (always hot) power to her medicine cabinet is located above it, where the fluorescent fixture is - the fixture itself contains the push button to turn the light on and off, so it would be up there that I would have to add the j-box and cover plate to connect the extra length of wiring to take down to a new wall switch. I have no idea where that cabinet wiring feeds from - I suspect from the ceiling light and fan switches next to the door on the adjacent wall...

Yeah, set up the same way our old unit was done, except the lighting fixtures were on the sides. The wiring should come into the top of the cabinet, where the cover inside is. As for where it runs from, ours was from the switch box in the bath, which power fed from the bedroom behind it from the basement, which also fed the bedroom in the front of the bath, along with hall light. Originally there were four circuits in this place. Where they had lighting fixtures in the basement, they fed one outlet and a lighting circuit from that fuse. That was how they did it back in the day.

I just ended up taking the old BX that ran into the Bath switch box, and placed it into a junction box in the attic, to continue the feed for the hall lighting. The bedroom in front of the house now has a new Romex feed going into the junction box downtairs, that feeds the back bedroom and hallway.

Only reason I did not pull the BX for the back bedroom, was due to that means tearing into walls, same for the hall, so I am left with those two along with the living room overhead, front entry and porch, and back entry and back porch, still with the old BX to those. Everything else in my place has been updated to all new Romex.

Some circuits though have junction boxes in the basement, since it was easier at that time to do that, then go box to box for outlets, when I redid the wiring when we bought this place. Now I am going back and slowly redoing circuits, so that the Romex goes from one box to the next, vs. having a bunch of junction boxes up in the joist bays downstairs.

You just triggered a memory... I recall the old metal pancake boxes in the attic of the house that must have fed down to the rooms below. I'm wondering if I could locate one over the bathroom that might open up some possibilities? Wouldn't look forward to that job, though. That house was built solid, as I found out when I was a teenager living there. Tried to run some phone line and discovered that the builder had placed bracing in between the studs - makes it hard to run cables down in the walls... Lol

Have you actually opened a box to look inside. My 1959 build house had all grounded wiring in it. I was able to upgrade to 3 prong recepticles real easy. Grounded wiring was starting to become more and more common around that time frame. When I bought my house all of the recepticles were two prong with the ground wire attached to the box.

dbb1959, I have not come across any fire blocking in the stud bays in my house. Of course then you get to pull out the flexbit, and hope that it does not bind inside when you are drilling up the wall.

I just thought that it was odd with our place, that the hall lighting came off the switch box in the bath, and the feed for the medicine cabinet, which originally was for a light above the sink (you could see the patch where the light sat), came off the switch box for our bedroom. I did end up using that junction box that I placed up in the attic, to feed the powervent for the attic, so it made for an easy install on that.

We did run into that at a friend's place, that has at leas what I have counted, eight generations of wiring, with K&T being the first gen.

Have you actually opened a box to look inside. My 1959 build house had all grounded wiring in it. I was able to upgrade to 3 prong recepticles real easy. Grounded wiring was starting to become more and more common around that time frame. When I bought my house all of the recepticles were two prong with the ground wire attached to the box.

That was Know A Little's experience, too, in the other post. Maybe I'll get lucky in that regard, otherwise I'll just be using a GFI marked accordingly.

My big concern is still getting the (possibly too short) wiring down to where I want to put a switch for the new lights.

It just dawned on me that I could use the junction box of the lighting fixture to add the extra length of wiring down to the switch (and back up to the new light above the cabinet). Might be a bit crowded in the box. But my junctions would be in an accessible j-box, but just hidden behind by the lighting fixture. That way I would not have to have an exposed blank plate on the wall where I add onto the length of wiring.